https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117726
--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Georg-Johann Lay <g...@gcc.gnu.org>: https://gcc.gnu.org/g:873cffc79209119a65aa657b0d427345e52b75c3 commit r15-5569-g873cffc79209119a65aa657b0d427345e52b75c3 Author: Georg-Johann Lay <a...@gjlay.de> Date: Wed Nov 20 12:25:18 2024 +0100 AVR: target/117726 - Better optimizations of ASHIFT:SI insns. This patch improves the 4-byte ASHIFT insns. 1) It adds a "r,r,C15" alternative for improved long << 15. 2) It adds 3-operand alternatives (depending on options) and splits them after peephole2 / before avr-fuse-move into a 3-operand byte shift and a 2-operand residual bit shift. For better control, it introduces new option -msplit-bit-shift that's activated at -O2 and higher per default. 2) is even performed with -Os, but not with -Oz. PR target/117726 gcc/ * config/avr/avr.opt (-msplit-bit-shift): Add new optimization option. * common/config/avr/avr-common.cc (avr_option_optimization_table) [OPT_LEVELS_2_PLUS]: Turn on -msplit-bit-shift. * config/avr/avr.h (machine_function.n_avr_fuse_add_executed): New bool component. * config/avr/avr.md (attr "isa") <2op, 3op>: Add new values. (attr "enabled"): Handle them. (ashlsi3, *ashlsi3, *ashlsi3_const): Add "r,r,C15" alternative. Add "r,0,C4l" and "r,r,C4l" alternatives (depending on 2op / 3op). (define_split) [avr_split_bit_shift]: Add 2 new ashift:ALL4 splitters. (define_peephole2) [ashift:ALL4]: Add (match_dup 3) so that the scratch won't overlap with the output operand of the matched insn. (*ashl<mode>3_const_split): Remove unused ashift:ALL4 splitter. * config/avr/avr-passes.cc (emit_valid_insn) (emit_valid_move_clobbercc): Move out of anonymous namespace. (make_avr_pass_fuse_add) <gate>: Don't override. <execute>: Set n_avr_fuse_add_executed according to func->machine->n_avr_fuse_add_executed. (pass_data avr_pass_data_split_after_peephole2): New object. (avr_pass_split_after_peephole2): New rtl_opt_pass. (avr_emit_shift): New static function. (avr_shift_is_3op, avr_split_shift_p, avr_split_shift) (make_avr_pass_split_after_peephole2): New functions. * config/avr/avr-passes.def (avr_pass_split_after_peephole2): Insert new pass after pass_peephole2. * config/avr/avr-protos.h (n_avr_fuse_add_executed, avr_shift_is_3op, avr_split_shift_p) (avr_split_shift, avr_optimize_size_level) (make_avr_pass_split_after_peephole2): New prototypes. * config/avr/avr.cc (n_avr_fuse_add_executed): New global variable. (avr_optimize_size_level): New function. (avr_set_current_function): Set n_avr_fuse_add_executed according to cfun->machine->n_avr_fuse_add_executed. (ashlsi3_out) [case 15]: Output optimized code for this offset. (avr_rtx_costs_1) [ASHIFT, SImode]: Adjust costs of oggsets 15, 16. * config/avr/constraints.md (C4a, C4r, C4r): New constraints. * pass_manager.h (pass_manager): Adjust comments.
